Update 12-27-2018: The CPU was clocked back down to an all core clock of 4.0GHz @ 1.20625V to keep temperatures under 71°C and this dropped the power consumption another 18W to 22W. The reasoning falls along this line of thought: why 4.1GHz @ 1.30625V when 4.0GHz @ 1.20625V is possible? This is a voltage stepping drop of over 16 steps of 0.00625V = 0.1V; a reduction of voltage by 7.66% with only a 2.44% reduction in clock speed and a reduction of nearly 16% in power consumption.
I built this PC for my sister. She is a mother now and she just needed a plain ol' PC and not something that could turn into a video titled as "What It Feels Like to Get a SFF Ultimate Unicorn Rainbow Gaming PC To Look Down Upon The Console Peasants While Eating Cake". Well, being the "mother first and everything else second" person she is now, she decided to let her daughter (and my niece) have the PC.
Initially, I told her that I planned to build a separate one for her daughter. She said not to worry about it as her laptop and being able to stream or video cast to a TV is good enough for her. I was saddened but, hey, I re-evaluated the build and decided that, heck, my niece needs to pick up on important computer skills anyways. We might as well let her start learning by our guidance and on her own (and, of course, parental controls will be in place as the internet can be a dangerous place for children). So, I ended up getting refreshed by this idea that occurred to us from the sudden change-of-plan. I remember learning software, hardware, coding, and everything else by trial-and-error and formal classes (online or in college). Might as well get her a better start than I had.
This Ryzen 7 2700 CPU will max out at 79°C with an all core overclock of 4.1GHz @ 1.30625V. This, basically, matches almost all of the frequency @ voltage tables most overclockers are getting with their 2700X CPUs. So, I think this particular 2700 is slightly above average.
The GTX 1080 Ti for this build is the notoriously bad cooling solution model from Gigabyte: Gaming OC 11G. Though the card is loud under a custom fan profile, the temperatures seem to stabilize at 74°C with a stabilized frequency range of 1873MHz to 1912MHz (it might have been 1911MHz, can't recall as of writing this). Again, is it loud? Yep. I may look into picking up a 120mm Asetek-based AIO as I have 2 NZXT Kraken G12 adapters lying around. The problem is, it'll look ugly but we'll see. If the noise is a big concern for my niece and my sister, I'll throw in the AIO cooler with the NZXT G12 adapter; otherwise, it's stable and it doesn't go past 74°C. The clocks could go much higher but that would require a severely aggressive fan curve and more than the 100% power limit. I am trying to keep this card at the 100% power limit to keep the system power consumption in that maximum efficiency range of 50% to 80% on the SeaSonic SFX PSU.
Speaking of which, the system total power consumption is approximately 475W to 515W. That keeps the PSU load between 73% and 79%. That is exactly what I required as the maximum power draw for the system. Unlike most SFF builders that focus on CPU, GPU, and case (in that order most of the time too), I centered it around the CPU, PSU, and case, in that specific order, prior to the build. Having the calculations allow me to throw in a GTX 1080 Ti was just a bonus. The original plan was to use a 1070 Ti or a 1080. After a week of the usual research and projections/calculations, this is the result and it worked out nicely. The system idles between 135W to 155W even with the all core 4.1GHz overclock.